Nearly 19,000 boys are starting secondary school with a reading age of a seven-year-old or below, government data has shown.

Some 9% of all 11-year-old boys in state schools in England did not reach level three in their reading tests this summer, statistics from the Department for Education reveal. This is the equivalent of 18,855 boys.

Level two is the standard expected of a seven-year-old and means pupils only have an understanding of simple texts and cannot read independently.

The government has said that by the age of 11, pupils should reach level four, at which point they are able to understand the major themes of a variety of texts and can to some extent read "between the lines".

The data, first obtained by the BBC, shows that in Nottingham, 15% of 11-year-old boys are reading at below level three. In Yorkshire and the Humber, the figure is 11%, while across the north-east, east Midlands and West Midlands, it is 10%.

The proportion of girls who did not reach level three in reading is 6%. On average, 8% of all pupils do not reach level three. Over the past 15 years, the proportion of pupils who have reached level four has jumped to 81% from 49%.

However, the statistics have cast doubt upon the success of government schemes to eradicate sub-standard reading skills among a minority of children. Over the past decade, the previous government spent more than £25m on early years education.

Michael Gove, the education secretary, said the coalition government would be introducing a reading test at the age of six to identify struggling pupils. The curriculum was "a closed book" for a child who starts secondary school with a reading age of a seven-year-old, he said.

He said headteachers in some parts of the country had proved that it was possible for pupils from disadvantaged backgrounds to achieve level four. These headteachers would help struggling schools, he said.

The reading tests are part of national exams in maths and English – known as Sats – that children sit at the end of primary school. Any school where fewer than 60% of pupils achieve level four in these tests will be "subject to intervention", Gove said. This could mean their headteacher is sacked.

"We still have this unbudging group of children who can't read ... let's see if we can identify these children at the age of six," he said. "We haven't had the focus we need on raising attainment."

Dylan William, professor of education at the Institute of Education, University of London, said children needed to have good reading skills more than ever.

"Twenty years ago, you got a lot of information from television. Now it's from the internet – you have to be more literate."

He said the problem was not identifying children who struggle with reading, it was finding money to tackle illiteracy. Intensive tuition and small class sizes helped children with sub-standard reading ages, he said.

Mike Welsh, chair of the National Association of Head Teachers, said many of the pupils who were not reaching level four in reading had special needs.

Last week, the government announced that £430 would go to each deprived pupil each year to try to narrow the gap in attainment between the poorest and richest children.